Chelsea's Premier League title challenge has been hit by a new Diego Costa row on the back of the striker becoming the latest Premier League player to receive a huge offer from China.
It is understood that head coach Antonio Conte has dropped Costa for today's Premier League trip to Leicester City in which leaders Chelsea are looking to bounce back from the defeat by Tottenham that ended their 13-game winning run.
Costa has not trained with the rest of the squad for the past three days after a bust-up over an injury with a club fitness coach, in which Conte got involved, and has not travelled to Leicester.
Chelsea are also aware that Costa (right) has received a staggering offer from China, with at least one club telling the Spain international that they are willing to pay him £30million-a-year net to leave Stamford Bridge. Chelsea owner Roman Abramovich is adamant that Costa will not force his way out and has told colleagues that he is willing to hold the 28-year-old to the two years remaining on his contract if he pushes for a move.
Tianjin Quanjian, who have signed Belgium midfielder Axel Witsel, are in the market for a striker and have been linked with an £80m bid for Costa.
Chelsea had been hopeful of agreeing a contract extension with Costa after the player had indicated that he was far happier with life in England, but the latest issue raises new doubts.
Costa is known for his combustible personality and his moods swing so dramatically that he can change from appearing to be desperate to leave to being happy once again in the space of a few days.
Chelsea will hope this latest episode quickly blows over, but it has given Conte a major headache as he tries to get his team on to another winning run after he collected the manager of the month award for December, setting a Premier League record by taking the trophy for three successive months.
Having punished Costa by leaving him out of the Leicester game, Conte is likely to play Eden Hazard through the middle with Pedro Rodriguez and Willian wide, as he did when Costa was suspended against Bournemouth.
Costa this week posted a series of pictures and videos on Instagram of him training on his own that could be seen as a reaction to the training ground incident with Chelsea's fitness guru. He is the Premier League's top scorer with 14 goals and had looked to have been tamed by Conte for a long period this season, when he went 11 games without being booked.
The pair had also struck a close personal relationship, despite Costa showing his frustration at being shouted at by Conte in the win over Leicester at Stamford Bridge by signalling that he wanted to be substituted.
Costa was warned not to repeat that behaviour and Conte has taken action after this week's falling-out, with Chelsea and Abramovich also adopting a strong stance that they will not be bullied by Chinese money.
Conte played down an incident between Costa and Pedro in the defeat at Tottenham, when Costa shouted at his team-mate for not making the correct run. There have also been reports of other instances in which Costa has let his passion get the better of him in training.
Conte hinted that he had at least one big decision to make for the Leicester match by saying: "I have to check a couple of situations and then decide. I don't want to say exactly what and give an advantage to our opponent."
Asked about whether he has ever had a player refuse to play for him in relation to Dimitri Payet going on strike at West Ham, Conte replied: "It's very difficult to talk and above all for me it's very difficult for me to talk about another player. For my club, for my players, we solve our problem if there are problems."
The headache over Costa could also influence Conte's decisions over strikers during this transfer window. He is interested in signing Fernando Llorente from Swansea and hopes to keep Michy Batshuayi at the club. Batshuayi is a loan target of West Ham, Marseille, Paris Saint-Germain and Lille.